German Cancer Research Center, Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.
Acta Oncol. 2010 Nov;49(8):1354-62. doi: 10.3109/0284186X.2010.485208. Epub 2010 Sep 15.
Currently, optimisation of the dose distribution and clinical acceptance are almost entirely based on the physical dose distribution and tumour control probability modelling is far from being routinely used as objective in treatment planning. For future individualised radiotherapeutic strategies, a reliable patient specific simulation model, taking into account customised tumour features, is needed to predict and improve treatment outcome.
To approach these demands, a single cell and Monte-Carlo based model was developed, which enables three-dimensional tumour growth and radiation response simulation. Tumour cells were characterised by cell-associated features such as age, intrinsic radio-sensitivity, proliferation ability, and oxygenation status, while capillary cells were considered as sources of a radial-dependent oxygen profile. Response to radiation was simulated by the linear-quadratic model, taking into account the lower radio-sensitivity of poorly oxygenated tumour cells.
The present study shows the influence of the model components and demonstrates the impact of the intra- and inter-tumoural radio-sensitivity heterogeneity on the treatment response.
The simulation model adequately delineates the importance of the above described selected parameters on tumour control probability, providing an insight into the interplay of different physical and biological parameters, and its relevance for an individual tumour response.
目前，剂量分布的优化和临床可接受性几乎完全基于物理剂量分布，肿瘤控制概率建模远未常规用作治疗计划的目标。对于未来的个体化放射治疗策略，需要一种可靠的患者特异性模拟模型，考虑到定制的肿瘤特征，以预测和改善治疗效果。
为了满足这些需求，开发了一种基于单细胞和蒙特卡罗的模型，能够进行三维肿瘤生长和辐射反应模拟。肿瘤细胞的特征是与细胞相关的特征，如年龄、固有放射敏感性、增殖能力和氧合状态，而毛细血管细胞被认为是径向依赖的氧分布的来源。通过考虑低氧肿瘤细胞较低的放射敏感性的线性二次模型来模拟对辐射的反应。
本研究显示了模型成分的影响，并演示了肿瘤内和肿瘤间放射敏感性异质性对治疗反应的影响。
该模拟模型充分说明了上述选定参数对肿瘤控制概率的重要性，深入了解了不同物理和生物学参数的相互作用及其对个体肿瘤反应的相关性。
